RPG Abfussor

i am thinking about placing a pair of RPG Abfussors in front of my tv to improve imaging and reduce the occasional brightness in the treble. $400+ for a pair of these in custom fabric seems a bit too much. would anyone like to share their experience with placing Abfussors in the center? are they very effective? many thanks in advance!
DIY Option:

thanks Launche for the info.
anyone has any comments on RPG Abfussors?